According to local news reports, some of the more intense fires are burning in the Giam Siak Kecil-Bukit Batu biosphere reserve and were deliberately set to clear land for palm oil plantations. The Giam Siak Kecil-Bukit Batu biosphere reserve contains just over 700,000 hectares of peat forest that sustains a wide range of plant and animal species including the Sumatra tiger, elephant, tapir, and sun bear.It is illegal to set fires to clear land in Indonesia, but the practice is common. The chief of the Indonesian National Disaster Mitigation Agency told ANTARA News that 99 percent of the fires in Sumatra and Kalimantan were deliberately set. Most fires occur during the dry season between April and October. The fires in 2014 started in February and have already forced Indonesia to declare a state of emergency because of poor air quality.